Adam Cooper is a fifteen-year-old boy living in colonial Lexington, Massachusetts with his family. He feels demoralized by his father, Moses Cooper, but finds consolation from Granny Cooper, his paternal grandmother. When a meeting of the township Committee is called on the evening of April 18th, Adam wishes to attend but his father questions whether or not his son is a man and has earned the right to attend the meeting. Instead of attending the meeting, Adam visits his neighbor Ruth Simmons, a distant relative whom he loves whom he loves and sees himself marrying in the distant future.
When his father returns home from the meeting, Adam eavesdrop as Moses tells his wife Sarah and Granny Cooper what happened, as the colonial communities prepare for a possible confrontation with the British army. During the late night early morning, a rider arrives in Lexington, waking up the community with news that the British army is on the march to Concord to take out supplies and ammunition that is being stored by colonists for a possible rebellion. Once the news of the night rider reaches the town the committeemen hold a muster for the militia, and Adam decides to sign the muster book and commit to fighting for the militia. His father is present when he is signing the muster and allows for it to happen. Moses Cooper no longer sees his son as a boy but as a determined man willing to fight for his family and community.
Both Adam and his father prepared themselves for the battle and a total of seventy militia men wait for the arrival of the British army. Moses Cooper argues